61 ideas
15945 | Second-order set theory just adds a version of Replacement that quantifies over functions [Lavine] |
15914 | An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one [Lavine] |
15921 | Collections of things can't be too big, but collections by a rule seem unlimited in size [Lavine] |
15937 | Those who reject infinite collections also want to reject the Axiom of Choice [Lavine] |
15936 | The Power Set is just the collection of functions from one collection to another [Lavine] |
15899 | Replacement was immediately accepted, despite having very few implications [Lavine] |
15930 | Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets [Lavine] |
15920 | Pure collections of things obey Choice, but collections defined by a rule may not [Lavine] |
15898 | The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine] |
15919 | The 'logical' notion of class has some kind of definition or rule to characterise the class [Lavine] |
15900 | The iterative conception of set wasn't suggested until 1947 [Lavine] |
15931 | The iterative conception needs the Axiom of Infinity, to show how far we can iterate [Lavine] |
15932 | The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs [Lavine] |
15933 | Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement [Lavine] |
15913 | A collection is 'well-ordered' if there is a least element, and all of its successors can be identified [Lavine] |
13258 | The 'aggregative' objections says mereology gets existence and location of objects wrong [Koslicki] |
15926 | Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine] |
13288 | Consequence is truth-preserving, either despite substitutions, or in all interpretations [Koslicki] |
14506 | 'Roses are red; therefore, roses are colored' seems truth-preserving, but not valid in a system [Koslicki] |
15934 | Mathematical proof by contradiction needs the law of excluded middle [Lavine] |
15907 | Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine] |
15942 | Every rational number, unlike every natural number, is divisible by some other number [Lavine] |
15922 | For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine] |
18250 | Cauchy gave a necessary condition for the convergence of a sequence [Lavine] |
15904 | The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine] |
15912 | Counting results in well-ordering, and well-ordering makes counting possible [Lavine] |
15949 | The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine] |
15947 | The infinite is extrapolation from the experience of indefinitely large size [Lavine] |
15940 | The intuitionist endorses only the potential infinite [Lavine] |
15909 | 'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine] |
15915 | Ordinals are basic to Cantor's transfinite, to count the sets [Lavine] |
15917 | Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine] |
15918 | Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine] |
15929 | Set theory will found all of mathematics - except for the notion of proof [Lavine] |
14505 | Some questions concern mathematical entities, rather than whole structures [Koslicki] |
15935 | Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine] |
15928 | Intuitionism rejects set-theory to found mathematics [Lavine] |
13289 | Structures have positions, constituent types and number, and some invariable parts [Koslicki] |
14501 | 'Categorical' properties exist in the actual world, and 'hypothetical' properties in other worlds [Koslicki] |
14495 | I aim to put the notion of structure or form back into the concepts of part, whole and object [Koslicki] |
13264 | If a whole is just a structure, a dinner party wouldn't need the guests to turn up [Koslicki] |
14497 | The clay is just a part of the statue (its matter); the rest consists of its form or structure [Koslicki] |
13280 | Statue and clay differ in modal and temporal properties, and in constitution [Koslicki] |
14496 | Structure or form are right at the centre of modern rigorous modes of enquiry [Koslicki] |
13279 | There are at least six versions of constitution being identity [Koslicki] |
14498 | For three-dimensionalist parthood must be a three-place relation, including times [Koslicki] |
13283 | The parts may be the same type as the whole, like a building made of buildings [Koslicki] |
13266 | Wholes in modern mereology are intended to replace sets, so they closely resemble them [Koslicki] |
14500 | Wholes are entities distinct from their parts, and have different properties [Koslicki] |
13281 | Wholes are not just their parts; a whole is an entity distinct from the proper parts [Koslicki] |
21515 | Incoherence may be more important for enquiry than coherence [Olsson] |
21514 | Coherence is the capacity to answer objections [Olsson] |
21496 | Mere agreement of testimonies is not enough to make truth very likely [Olsson] |
21499 | Coherence is only needed if the information sources are not fully reliable [Olsson] |
21502 | A purely coherent theory cannot be true of the world without some contact with the world [Olsson] |
21512 | Extending a system makes it less probable, so extending coherence can't make it more probable [Olsson] |
14504 | The Kripke/Putnam approach to natural kind terms seems to give them excessive stability [Koslicki] |
13285 | Natural kinds support inductive inferences, from previous samples to the next one [Koslicki] |
13287 | Concepts for species are either intrinsic structure, or relations like breeding or ancestry [Koslicki] |
13284 | Should vernacular classifications ever be counted as natural kind terms? [Koslicki] |
13286 | There are apparently no scientific laws concerning biological species [Koslicki] |